| Scripting Resources for DigitalMicrograph™ |
Function: Standard Deviation |
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Function |
Function to compute the standard deviation (sigma n-1) of an image, or a set of values passed in as pixel values in an image. The number of data points (n), the mean and the sum are also returned. |
Version |
version:20160604, v2.0 |
Author |
D. R. G. Mitchell |
Acknowledgements |
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Comments |
Data is passed into the function as an array (image). This is the front-most image. To analyse numerical data - create a one dimensional image, paste the values into the image (array) and pass it to the function. |
System Requirements |
Should be compatible with all recent versions of DigitalMicrograph. |
Known Issues |
If you used the previous version of this standard deviation function in any of your scripts - please update the code with this version, as it corrects a bug. |
Supported |
Yes |
Included Files |
Main script file. |
Source Code |
// Function to compute the standard deviation (sigma n-1) of an image, or // a set of values passed in as pixel values in an image. The // number of data points (n) the mean and the sum are also returned. // This emulates the functionality in the Analysis/Statistics menu
// D. R. G. Mitchell, adminnospam@dmscripting.com (remove the nospam to make this email address work) // version:20160604, v2.0, June 2016, www.dmscripting.com
void StandardDeviation(image arrayimg, number &stddev, number &n, number &mean, number &sum) { mean=mean(arrayimg) number xsize, ysize getsize(arrayimg,xsize, ysize) n=xsize*ysize
image nminusmeansqrd=(arrayimg-mean)**2 number sumsqrdiff=sum(nminusmeansqrd) stddev=sqrt((sumsqrdiff/(n-1))) sum=sum(arrayimg) }
// main program starts here
number nodocs=countdocumentwindowsoftype(5) if(nodocs<1) { showalert("Ensure an image is shown front-most.",2) exit(0) }
image front:=getfrontimage()
// Declare some variables
number stddev, meanval, nopixels, sum
// Call the standard deviation function
StandardDeviation(front, stddev, nopixels, meanval, sum)
// Output the results
result("\nNo of values = "+nopixels+"\nSum = "+sum+"\nMean = "+meanval+"\nStandard Deviation = "+stddev+"\n")
showalert("No of values = "+nopixels+"\nSum = "+sum+"\nMean = "+meanval+"\nStandard Deviation = "+stddev,2) |